Because of lower silicon purity, polycrystalline solarpanels are not quite as efficient as monocrystalline solarpanels. Lower space-efficiency. You generally need to cover a larger surface to output the same electrical power as you would with a solar panel made of monocrystalline silicon.

For what it's worth, I had a Renogy Poly starter kit (100w) on mine for the three years I had it, and it worked fine for a pair of GC2 batteries, never had an issue. Sold the boat, but I expect it'll continue to work fine.

I bought two Renogy 100W panels for a shoreside application. They worked just fine, but when I was doing some bypass diode experiments I noticed that one of the panels had a problem. I removed the cover from the junction box and discovered that the midpoint connection from the two bypass diodes was *not* connected to the midpoint of the 36-cell string. The diodes were good, but the soldering to the panel hadn't made contact.

This didn't affect the operation of the panel when used by itself, but would be a problem in a series-connected design.

My two panels make up a very small sample size, but that's what I saw.